Method for updating device descriptions for field devices in process automation technology

ABSTRACT

A method for updating device descriptions for field devices in process automation technology by loading the required descriptions from an external server (S), by means of an application program, into a controller (for example, PC 1 ; PC 2 ).

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation application which claims the benefitof U.S. application Ser. No. 10/522,586, which was filed on Jan. 26,2005, which is the U.S. National Stage of PCT/EP2003/007839, filed on 18Jul. 2003.

FIELD OF THE INVENTION

The invention relates to a method for updating device descriptions forfield devices of process automation technology.

BACKGROUND OF THE INVENTION

In the field of process automation technology, in many cases, fielddevices are used for registering and influencing process variables.Examples of field devices are temperature measuring devices, whichregister the temperature of a medium; flow rate meters, which registerthe flow rate of a medium in a section of piping; or fill level meters,which register the fill level of a liquid or bulk goods in a container.

Field devices are normally connected via a data or field bus withsuperordinated control units, e.g. process control systems PCS or anengineering system, from which the process activity is controlled ormonitored, and also from which direct access to individual field devicesis possible. As a result of the direct access to the field device,settings at the field device can be changed from the control unit, ordiagnostic functions of the field device can be called up. In thecontrol unit, the measurement values of the different sensors areevaluated or monitored, and, for process control, the appropriateactuators are activated. Data transfer between field device and controlunits is carried out according to known international standards forfield buses, such as e.g. HART®, Foundation Fieldbus®, Profibus®, orCAN-Bus®, etc.

Frequently in process automation technology, field devices fromdifferent manufacturers are used. The servicing, or operating, of fielddevices is carried out by means of PC-based applications, whichespecially support the parameterization, start-up, and diagnostics ofindividual field devices, in part also graphically.

Examples for such display- and service-programs are AMS® ofFisher-Rosemount, Simatic PDM® of Siemens, Smart Vision® of ABB, WO® ofVega, or Commuwin® II of Endress+Hauser.

In order to enable the servicing of different field devices from acontrol unit, the functionality of the respective field device must beknown to the control device. The functionality of the field device isdescribed by means of a so-called device description (DeviceDescriptions DDs). For this, a special language, the device descriptionslanguage, is available. By means of this standardized language, thenecessary information concerning the functionality of a specific fielddevice can be made available to other bus participants, especially thecontrol system, or an additional service device (handheld device).Normally the device descriptions are created by the field devicemanufacturer, and are delivered with the respective field device e.g. ondisk.

At the start-up of the field device, the appropriate device descriptionis then installed from the application program.

This is problematic in that device descriptions are periodically updatedby the manufacturer. The updated device descriptions (updates) must thenbe sent to the corresponding user, and are then subsequently installedmanually using the application program.

In this procedure, it is not guaranteed that the user is, in fact, usingthe most recent update of the device description. Especially in the caseof safety-related process applications, it is mandatory that the mostrecent data description is made available to the user, especially whenprogramming errors (bugs fixing) have appeared in a version of a devicedescription.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method for updatingdevice descriptions for field devices in process automation technology,which method does not have the above-mentioned disadvantages, and whichespecially enables a simpler and more secure updating.

This object is achieved by means of an application program in a controlunit, for example PCs, which downloads device descriptions for fielddevices from an external server.

An essential idea of the invention includes the storing of devicedescriptions for field devices on a central server, and that, in acontrol unit, an application program, which requires correspondingdevice information for servicing a field device, downloads such from theserver, following query of the device type of the field device.

BRIEF DESCRIPTION OF THE DRAWING

The invention will now be explained in greater detail on the basis of anexample of an embodiment illustrated in the drawing, the figure of whichshows as follows:

FIG. 1 a schematic representation of a process automation installation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a process automation installation with multiple fielddevices F1, F2, F3, which are connected with a firm, or company, networkby way of a data or field bus D and a gateway G. The field devices F1,F2, F3 can be e.g. pressure meters, temperature meters, or flow ratemeters, etc. In addition to the field devices, a remote I/O is alsoconnected to the data bus. By way of the remote I/O, HART® field devicescan be connected to the data bus D. The data bus can be e.g. aFoundation Fieldbus® H1-bus. The firm network F works e.g. according tothe Ethernet standard (TCP/IP protocol). Two computers (e.g.workstations or PCs) PC1, PC2 are connected to the firm network F ascontrol units, which serve for the control, engineering, or monitoringof the process system. Furthermore, the firm network F is connected witha firewall IS, which communicates via the Internet I with a remoteserver S.

The method of the invention will now be described in greater detail. If,e.g. in a control unit, e.g. computer PC1, a special application e.g.for servicing, configuring, parameterizing, or troubleshooting a fielddevice F1, F2, F3 is running, which, for its operation, requires devicedescriptions for field devices, then the application program sends arequest to the field device to be serviced e.g. F1, and requests thedevice type of this field device. If the application program in thecontrol unit does not possess the required information for this specificfield device F1, or does not possess this required information in theupdated version, then the necessary device descriptions are downloadedvia the Internet from the server S, on which the most up-to-date devicedescriptions are stored.

In this way, the most recently updated device descriptions are alwaysavailable in the application program. In order to avoid an unnecessarydata transfer, the updated device information is only downloaded fromthe server S when it differentiates the device information saved in thecontrol unit PC1 from that stored in field device F1. This is especiallythe case at the start-up of the field device, because at this time,still no information concerning this field device is stored in thecontrol unit PC1.

Since device descriptions can change over time due to updates and errorcorrections (bug fixing), the application program queries the server Sin regular intervals, as to whether changed device descriptions areavailable.

Most simply, the connection between control unit PC1 or PC2 and server Sis accomplished via the internet I, through the firewall IS.

The connection between the control unit PC1 and field device F1 isaccomplished via a data bus D. The display and service program CommuWinII®, of the firm Endress+Hauser, allows a graphic deviceparameterization, device diagnostics with error codes and textualexplanations, as well as providing the device servicing, or deviceoperating. For this application, device descriptions DDs are required.

Advantageously, the device descriptions, therefore, are the devicedescriptions DD for the field devices F1, F2, F3.

Since not only device descriptions can change over time, but alsofirmware for specific field devices, it makes sense to download thecurrent firmware from the server S as well.

As a result of the query of the application program to the server S,specific information of various field devices and various field deviceusers is transferred to the server S. This information can be bufferedin the server S for statistical purposes. For the user, it is certainlyvery advantageous when the updated device description, and/or theupdated firmware, is automatically installed.

A further advantage of the method of the invention is that preconfigureddevice descriptions for specific applications of a field device arestored in the server S, and, following appropriate selection by theuser, are loaded from the application program. The parameterization offield devices is thereby greatly simplified.

To some extent, application programs (e.g. ToF-Tool® of Endress+Hauser)also use the appropriate national language.

The device descriptions are simply stored in the respective nationallanguage. In this way, the required information is made available to theuser in his/her national language, and translation errors are easilycorrected. With the aid of the method of the invention, it is assuredthat the most recent device descriptions are always available to anapplication program.

The invention claimed is:
 1. A method for updating device descriptionsfor different field devices, sensors or actuators, for determining andinfluencing process variables in process automation technology, wherebythe field devices are connected via a field bus, whereby in each case adevice description describes the functionality of the correspondingfield device in a standardized language and whereby a control unit andan external server are employed, and whereby from the control unit aprocess activity is controlled or monitored and from which direct accessto individual field devices is possible, wherein data transfer betweenthe field devices and the control unit is carried out according to aninternational standard for field buses, comprising the steps: storingpreconfigured device descriptions for specific applications of the fielddevices on a central server connected to the field bus via Internet,storing and running an application program in the control unit forservicing, configuring, parameterizing, or troubleshooting the fielddevice, which application program requires device descriptions for fielddevices for its operation; downloading from the central server via theinternet, by the application program in the control unit, thepreconfigured device description of the corresponding field device to beserviced; wherein following a query of the device type of the fielddevice corresponding device information for servicing the field deviceis downloaded from the central server.
 2. The method as claimed in claim1 wherein in the case that a preconfigured version of the devicedescription of the field device is not available in the control unit thenecessary device descriptions are downloaded via the internet from thecentral server.
 3. The method as claimed in claim 1 wherein the mostup-to-date device descriptions are stored on the central server.
 4. Themethod as claimed in claim 1 wherein the updated device information isonly downloaded from the central server when the device informationsaved in the control unit differentiates from that stored in the fielddevice.
 5. The method as claimed in claim 1 wherein followingappropriate selection by a user preconfigured device descriptions forspecific applications of a field device which are stored on the centralserver are loaded from the application program.
 6. The method as claimedin claim 1 wherein the device descriptions on the central server arestored in respective national language.
 7. The method as claimed inclaim 1 wherein a current firmware for specific field devices aredownloaded from the central server as well.
 8. The method as claimed inclaim 1 wherein as a result of the query of the application programspecific information of various field devices and various users istransferred to the central server.